Unit 1 AOS 1 Outcome 2

Question 1

Justice

Answer 1

Commitment to fairness, ensuring no unfair burden on specific people

Question 2

Reasons why cells replicate in multicellular organisms

Answer 2

• Restore nucleus to cytoplasm ratio
• Growth, repair and development
• Reproduction

Question 3

Reasons why unicellular organisms replicate

Answer 3

Reproduction

Question 4

Prokaryotic cell cycle

Answer 4

Replicating cells through binary fission

Question 5

Binary fission

Answer 5

1. Replicate circular DNA chromosome + cell lengthens
2. Chromosomes move to either end of the cell
3. Cell membrane pinches, splitting the cell in 2

Question 6

Eukaryotic cell cycle

Answer 6

Replicating cells in 3 main phases:
1. Interphase
2. Mitosis
3. Cytokinesis

Question 7

Interphase

Answer 7

First part of eukaryotic cell cycle, beginning immediately after cell replication. 3 main phases - G1, S and G2.

Question 8

G1 phase

Answer 8

First phase of interphase, growing, gaining energy, and metabolic processes

Question 9

S (synthesis) phase

Answer 9

Second phase of interphase, replicating DNA, ending up with 46 duplicated chromosomes

Question 10

G2 phase

Answer 10

Third phase of interphase, more growing and energy, preparing for mitosis

Question 11

Mitosis

Answer 11

Continuous process, dividing the nucleus, comprised of 4 stages - Prophase, Metaphase, Anaphase, Telophase

Question 12

Prophase

Answer 12

First phase of mitosis where chromosomes condense, spindle fibres connect to centromere of sister chromatids, nucleus breaks down

Question 13

Metaphase

Answer 13

Second phase of mitosis where spindle fibres line chromosomes in the equator of the cell

Question 14

Anaphase

Answer 14

Third phase of mitosis where spindle fibres retract, separating sister chromatids to opposite poles of the cell

Question 15

Telophase

Answer 15

Final phase of mitosis where nucleus begin to reform and cell begins to split into 2 genetically identical daughter cells

Question 16

Cytokinesis

Answer 16

Final stage of eukaryotic cell cycle, where cytoplasm splits

Question 17

Centromere

Answer 17

Connecting piece of sister chromatids

Question 18

Centriole

Answer 18

Structure made of microtubule fibres

Question 19

Spindle Fibre

Answer 19

Clusters of microtubules that grow from centrioles

Question 20

Chromatin

Answer 20

DNA wrapped around proteins

Question 21

Cell cycle checkpoints

Answer 21

Checkpoints in the eukaryotic cell cycle to make sure daughter cells are damage free. The 3 checkpoints are in G1, G2 and Metaphase

Question 22

G1 checkpoint

Answer 22

First checkpoint, in G1 part of interphase, where DNA is checked by a protein called p53 which is a tumour suppressor

Question 23

G2 checkpoint

Answer 23

Second checkpoint, in G2 part of interphase, making sure replicated DNA is correct

Question 24

Metaphase (M) checkpoint

Answer 24

Third and final checkpoint, making sure spindle fibres are connected to the correct sister chromatids, and are align correctly

Question 25

Tumour suppressor genes

Answer 25

Proteins that signal the cell to reduce cell division, repair DNA or initiate cell death

Question 26

Proto-onco genes

Answer 26

Genes in the DNA that produce protein that initiate the cell cycle

Question 27

Apoptosis

Answer 27

Genetically regulated and controlled cell death

Question 28

Blebs

Answer 28

Protrusions of the cell membrane

Question 29

Phagocytosis

Answer 29

The process of Phagocytes cleaning apoptopic bodies

Question 30

p53

Answer 30

A protein that slows cell division or initiate death. A Tumour suppressor gene

Question 31

Things that begin apoptosis

Answer 31

- Cells at the end of their natural life - Dysfunctional, diseased, or diseased cells - Excessive amounts of cells

Question 32

Apoptosis pathways

Answer 32

Extrinsic pathway Intrinsic pathway

Question 33

Intrinsic pathway

Answer 33

Known as the mitochondrial pathway, apoptosis occurs this way when cells are under stress, causing apoptosis to occur through damaged mitochondria

Question 34

Extrinsic pathway

Answer 34

Known as death receptor pathway, death receptors signal apoptosis to occur

Question 35

Process of apoptosis

Answer 35

Cells shrink -> blebs form -> apoptopic bodies form -> phagocytes clean apoptopic bodies

Question 36

Necrosis

Answer 36

Uncontrolled cell death resulting in messy explosions

Question 37

Deviant cell behaviour

Answer 37

When regulated cell death doesn't occur as it is meant to, resulting in cell production exceeding cell loss or cell loss exceeding cell production.

Question 38

Cancer

Answer 38

Uncontrolled cell cycle, excess cell production, cancerous tissue reproduces faster than regulated cell cycle

Question 39

Psoriosis

Answer 39

Inflamed raised patches of skin, occurs when cells are produced too fast

Question 40

Neurodegenerative diseases

Answer 40

When cell loss exceeds cell production, conditions such as parkinsons and alzheimers can occur

Question 41

Stem cells

Answer 41

Unspecialised cells that can divide and renew, and can replenish specialised cells

Question 42

Self renewal

Answer 42

Stem cells can self renew meaning that by division, specialised cells can be replaced

Question 43

Cell differentiation

Answer 43

The process of cells becoming specialised

Question 44

Totipotent Stem cells

Answer 44

Can renew all types of specialised cells including placental tissue

Question 45

Pluripotent stem cells

Answer 45

Can replace many types of specialised cells, including germ layers

Question 46

Multipotent stem cells

Answer 46

Can differentiate to closely related specialised cells within a certain family

Question 47

Unipotent stem cells

Answer 47

Can only produce a singular type of cell but can self renew.